"The Obama administration is cracking down on BP as the oil company overhauls its massive refinery in northwest Indiana, one of the largest sources of air pollution in the Chicago area.

In response to a petition from environmental groups, the U.S. Environmental Protection Agency on Monday ordered Indiana regulators to revamp a new operating permit for the Midwest's biggest refinery. The groups, along with elected officials in Illinois, contend Indiana had allowed the oil giant to avoid stringent requirements under the federal Clean Air Act.

Tougher pollution limits could help relieve problems with lung-damaging soot and smog in the metropolitan area that stretches around the tip of Lake Michigan.

In a 24-page order, the agency directed Indiana to take a new look at several sources of air pollution at the Whiting refinery, 15 miles southeast of downtown Chicago. The results are due in 90 days."